System and Method For Precision Grinding and Self-Leveling Installation of Concrete Masonry Systems

ABSTRACT

A stackable building block  1102  for constructing a masonry wall includes a front section  502  having an outer surface, an inner surface, a bottom surface, and a top surface. The top surface may be divided into a higher surface  1111  positioned between two lower surfaces  1109 . The building block also has a rear section  504  substantially parallel to the front section having an outer surface, an inner surface, a bottom surface, and a top surface. Two or more webs  1106  coupling the inner surface of the front section to the inner surface of the rear section have a top surface and a bottom surface. Two or more pairs of lugs  508  may extend above the top surface of the front section and the top surface of the rear section. During manufacturing the higher surface of the top surface is ground to a precision height. During assembly of the stack building block, a thin set mortar, grout or adhesive is used between successive courses.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application claims priority to U.S. provisional PatentApplication 61/053,463 filed on May 15, 2008 entitled “Web Offset LugDry-Stack System”, which is incorporated fully herein by reference.

TECHNICAL FIELD

The present invention relates to stack concrete masonry systems forbuilding structural load bearing and non-load bearing walls and, moreparticularly, to a system and method that utilizes precision grinding ofa small top portion of masonry blocks in addition to a masonry adhesiveor grout that “self-levels” the masonry blocks to provide for accurateand simplified assembly of concrete masonry.

BACKGROUND INFORMATION

Present masonry construction techniques provide for essentially twomasonry construction techniques: the traditional mortared blocktechnique where motor is place between each block both on a horizontalface as well as a vertical face; and a newer technique of dry stackingwhere blocks are designed to be simply placed one upon the other in somearrangement without any mortar between the blocks themselves (althoughcement may be later placed in spaces within the stacked blocks). Anadvantage of dry stack masonry systems is that the labor component ofinstallation can be dramatically reduced. Some studies have shown thatdry stack masonry systems are up to ten times faster to install thanconventional joint mortared masonry systems and require a significantlyless skilled labor force to install them. Because these systems do notuse bonding mortar to provide joint support, it may be necessary to useother means of developing wall strength to meet various building codes.

For example, various building codes may require dry-stacked concreteblock cells to be filled with cement in order to provide specifiedstructural integrity. Some applications may require all the cells to befilled with concrete. Other applications may require the concrete to bepoured into distinct vertical columns and only in certain cells or coresof the block. These applications may require cells, for example, to befilled generally at four foot on center increments and/or at wallcorners and jambs of windows and doors or various load points. A generaloverview of the use of current dry stack methods in masonry wallconstruction can be found in National Concrete Masonry Association's(NCMA) technical publication TEK 14-22 “Design and Construction ofDry-Stack Masonry Walls” Incorporated herein by reference.

Currently, the accepted practice for constructing with concrete masonryunits using the traditional mortared technique (structural concreteblock) requires that the blocks be mortared together with a codeapproved masonry mortar mix. Typical masonry mortar mixes containportland cement, lime and mason sand, as well as additives for improvingworkability. These masonry mortar mixes are applied and installed by anexperienced mason using a trowel. The trowel has been used inconstructing masonry walls for thousands of years. As a result, theavailability of a skilled mason applying mortar with a trowel becomesthe limiting factor in the how fast a masonry wall can be constructed.The amount of labor cost to install a masonry wall is currently in therange of 66% to 75% of the overall masonry construction costs.

There have been attempts to change the dynamics of the masonryconstruction market in an attempt to lower the labor expenses associatedwith typical block concrete construction. As a result, many systems haveattempted to eliminate the need for mortar during construction of thewall. The dry-stack masonry wall describe above is one such example. Byeliminating the mortar step, the installer should be able to go muchfaster in erecting walls. The issue with current mortar less systems,however, is that these systems do not have sufficient height control toduplicate the height control capability of a mortar joint between blockthat can be adjusted to take care of concrete masonry units block heightirregularities. The mortar, besides providing bonding and sealing, alsoserves as a leveling mix that provides a way for the wall builder toadjust the height and level of the courses to meet the specificdimensions for openings and top of wall elevations. Moreover, dry stackmasonry walls may not have the same load strength as traditionalmortared masonry walls and many building codes recognize this and arereluctant to change to allow dry-stack masonry walls in manyapplications.

Accordingly, a need exists for a system and method that provides amasonry block having predetermined area (that is smaller than full topsurface area of the masonry block) that can be ground down to a preciselevel to ensure that there will be no “rocking” or un-levelness in thestacked blocks and that are installed using a non-trowel applied groutor adhesive which serves to adhere the blocks together without the needto use skilled masons using trowels.

SUMMARY

In order to solve the problems associated with conventional mortaredmasonry and with the mortar less/dry-stacked methods of building masonrywalls, a new system was developed. This novel system combineswet-stacking with self-leveling and a precision grinding method. Thissystem eliminates the need for trowel-applied mortar. The systemdramatically reduces the need for highly skilled masons in the overallconstruction crew, while also providing nearly the speed of conventionaldry-stack systems.

In one aspect the invention features a method of producing a stackablebuilding block for constructing a masonry wall. The method comprises theacts of molding a concrete block having a front section coupled to andsubstantially parallel with a rear section. Each front and rear sectionshas a bottom surface and a top surface, wherein the top surface on boththe front and rear sections includes a central region having a heightwhich is greater than the first and second end regions located on eitherside of the central region. The method also includes grinding thecentral region of the top surface of the front and rear block sectionsto a predetermined height.

The method of producing a stackable building block for constructing amasonry wall utilizes a building block that is a dry stackable concreteblock. Alternatively, the method of producing a stackable building blockfor constructing a masonry wall utilizes a building block that is a wetstackable concrete block.

In another aspect of the invention, the method of producing a stackablebuilding block for constructing a masonry wall includes a central regionthat has an undulating surface.

In a further embodiment of the invention, the method of producing astacked building block wall utilizing the stackable building blockfurther comprises applying a flowable, thin set mortar onto the topsurface of the stackable building block using a high speed applicator.The high speed application may be a grout bag. The mortar is applied toa thickness of ⅛ of an inch or less.

In another embodiment of the invention, the grinding of the highersurface of the top surface is precision ground to provide a stackbuilding block of a specific precision height.

In an additional embodiment of the invention, the central region of thetop surface further includes a plurality of indents or serrations orchannels. The method of producing a stacked building block wallutilizing the stackable building block further comprises the acts ofapplying a flowable, thin set mortar onto the top surface of thestackable building block using a high speed applicator and allowing themortar to enter the plurality of indents or serrations or channels onthe central region of the top surface, wherein the addition of themortar does not significantly increase the specific precision height ofthe stackable building block.

Another embodiment of the application further comprises stacking asecond duplicate stack block staged halfway off-center and stacking athird duplicate stack block staged halfway off-center in a directionopposite and adjacent to the second stack block.

In a further aspect of the invention, the stack building block has achamfered or beveled edge on one more exterior edges of the buildingblock.

It is important to note that the present invention is not intended to belimited to a system or method which must satisfy one or more of anystated objects or features of the invention. It is also important tonote that the present invention is not limited to the preferred,exemplary, or primary embodiment(s) described herein. Modifications andsubstitutions by one of ordinary skill in the art are considered to bewithin the scope of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other features and advantages of the present invention will bebetter understood by reading the following detailed description, takentogether with the drawings wherein:

FIG. 1A is a top plane view and FIG. 1B is a front cross sectional sideview of a prior art conventional dry stack block assembled into a linearwall structure.

FIGS. 2A, 2B, and 2C are views of the present invention comprising twodry-stack units, a stretcher unit and a corner unit shown here assembledinto a wall structure turning a 90 degree corner according to anexemplary pin embodiment.

FIG. 3 is a perspective view of present invention comprising the twodry-stack units, the stretcher unit and the corner unit shown hereassembled into a linear wall structure according to the exemplary pinembodiment.

FIG. 4A is a top plane view and FIG. 4B is a side profile view of thestretcher unit according to an exemplary embodiment of the inventionwith webs at non-right angles.

FIG. 5A is a top plane view and FIG. 5B is a side profile view of thestretcher unit according to an exemplary embodiment of the inventionwith webs at right angle.

FIG. 6A is a top plane view; FIG. 6B is a cross sectional view; FIG. 6Cis a front profile view; and FIG. 6 d is a side profile view of thestretcher unit according to an exemplary edge-grinding and exemplary pinembodiment.

FIG. 7A is a top plane view; FIG. 7B is a front profile view; and FIG.7C is a side profile view of the corner unit according to an exemplarypin embodiment.

FIG. 8A is a top plane view and FIG. 8B is a front cross sectional sideview of the stretcher unit assembled into a linear wall structure.

FIG. 9 is a perspective view of the stretcher units stack-bondedconstruction.

FIG. 10A is a top plane view; FIG. 10B is a cross sectional view; FIG.10C is a front profile view; and FIG. 10 d is a side profile view of thestretcher unit according to an exemplary chamfered edge embodiment withprecision ground top and recessed lug edge.

FIG. 11A is a side profile view; FIG. 11B is a top plane view of thestretcher unit according to an exemplary edge-grinding embodiment; FIG.11C is a side profile view of the stretcher unit.

FIG. 12A is a side profile view and FIG. 12B is a top plane view of thestretcher unit according to a second exemplary edge-grinding embodiment.

FIG. 13A is a front profile view and FIG. 13B is a top plane view of thecorner unit according to an exemplary edge-grinding embodiment.

DETAILED DESCRIPTION

A corner wall structure 200 may use a stretcher unit 202 and a cornerunit 204 to construct the corner and straight portions of a wall, asshown in FIGS. 2A, 2B, and 2C. The stretcher units 202 have lugs 206that extend above the top of the stretcher unit 202. The next course ofstretcher units is placed on top of the previous layer of stretcherunits. The lugs 206 of the previous layer of stretcher units extend intothe cells of the next course of stretcher units. The lugs provide faceshell alignment, lateral strength, and lock together successive layersof units.

The stretcher units 202 have a front section and a rear section. One ormore webs or ribs couple the front section to the rear section. The oneor more webs may extend just below the top surface of the stretcher unit202 or may extend all the way to the top surface of the stretcher unit202. The stretcher units 202 also have lugs that extend above the topsurface of the stretcher unit 202. The stretcher unit 202 and otherexemplary embodiments of the stretcher unit 202 will be described ingreater detail later herein. The corner units 204 may also have a frontsection, rear section, and one or more webs coupling the front sectionand rear section. The corner unit also has a side section. The sidesection provides a ninety-degree corner in the wall. The corner unit 204provides a uniform surface at the corner of the wall. The corner units204 are staggered with each successive row. The corner unit 204 andother exemplary embodiments of the stretcher unit 202 will be describedin greater detail later herein.

The corner unit 204 may not have lugs extending from the top. Deformablepegs 208 in peg holes 210 may be used to position the corner unit 204during construction. The deformable pegs 208 may be made of, forexample, copper tubing. The exemplary dimensions of the copper tubingmay be about ¼ inch diameter with length of about one inch. The coppertubing allows the peg 208 to deform with relative little force andremain in the deformed shaped. The distorted shape of the deformable peg208 holds the units in a plumb and square position during constructionphase. The deformable pegs 208, are not limited to a metal tubing. Thedeformable peg 208 may be made from a variety of materials thatsufficiently lack memory and provide desired strength, for example,metals, metal alloys, composites, plastics, and polymers. The deformablepegs 208 are not limited to a tubular structure. The deformable peg 208may be, for example, solid, a variety of cross-sectional shapes, and/ora variety dimensions.

Referring to FIG. 7, a top receiving hole 710 and a bottom receivinghole 712 may be provided prior to stacking of the units. The deformablepeg 208 is positioned within one of the top or bottom receiving holes710, 712. For example, the deformable peg 208 may be positioned with thetop receiving hole 712 after the respective unit has been positioned.The top and bottom receiving holes 710, 712 may be sized to provide africtional fit. This allows for the depth of the receiving holes 710,712 to be greater than an insertion length of the deformable peg 208.The deformable peg 208 may be position within a receiving hole 710, 712and lightly hammered or pressed, for example by thumb pressure, into thedesired length, for example half way into the top receiving hole 710allowing the other half to extend above the surface of the block unit toreceive the bottom receiving hole 712 on the next successive unit.

The next successive unit is positioned so that the deformable peg 208aligns with the bottom receiving hole 712. The top and bottom receivingholes 710, 712 may be constructed in a variety of methods. For example,the receiving holes 710, 712 may be molded or punched in the block unitprior to curing, the receiving holes 710, 712 may be drilled into theblock unit on-site, or a combination of construction. For example, thetop receiving hole 712 may be punched in the unit prior to curing andthe bottom receiving hole 710 may be drilled. The positioning of thereceiving holes 710, 712 may be dependent on the number of pegs perblock unit, the overall wall construction shape (i.e. 90 degree corner,45 degree corner, or end of a wall), and other construction aspects.

Once the unit is maneuvered in place, the unit may be positioned forgreater accuracy by tapping the unit with a mallet or other tool. Thepositioning may be accomplished immediately after place of the unit orafter successive layers of units have been positioned. The positioningby tapping the unit causes the deformable peg 208 to bend or deform intoa new semi angled shape. The new shape aids in holding the units in acorrect position or place until concrete secures the wall permanently.The deformable peg may allow for multiple positioning. For example aunit may be tapped successively throughout the dry stacking process ofthe wall in order to adjust positioning of the wall. The deformable pegs208 may be used for corners or other portions of the wall in whichadditional adjustment may be beneficial.

The corner unit 204 may not have lugs extending from the top. The cornerunit may be used in a straight wall portion, as shown in FIG. 3. Thespacing and alignment of lugs, as will be discussed later herein, allowsthe corner section to be placed within a straight portion of the wall.The lugs of the lower stretcher units 202 extend into the cells of thecorner unit 204 without interfering with the side section or the webs ofthe corner unit.

FIG. 4A is a top plane view and FIG. 4B is a side profile view of astretcher unit 400 according to an exemplary embodiment of the inventionwith webs at non-right angles. The stretcher unit 400 may have a heightof eight inches and a length of sixteen inches. The stretcher unit 400has a front section 402 and a rear section 404. The front section 402and the rear section 404 may have a thickness of one and a quarter (+/−)inches. One or more webs 406 couple the front section 402 to the rearsection 404. The webs 406 may have a thickness of one and a half inches(+/−). The webs 406, according to this embodiment, are symmetricallyangled between the front section 402 and the rear section 404. Each web406 has a pair of lugs 408 extending from the top surface of the web.The lugs 408 may extend above the top surface by ⅜ (+/−) of an inch. Thelugs may have a width and thickness of one inch (+/−). The angled webs406 allow the stretcher units to be stacked in a staggered fashionwithout the lugs interfering with the web of a successive layer ofstretcher units. The web of the successive layer of stretcher unitsstraddles each pair of lugs 408. The stretcher unit is supported in thelateral direction by a lug positioned between the inner surface of thefront or rear section and the web.

The exemplary embodiments shown in FIGS. 4A and 4B may also includeround lugs. The lugs have a round top portion, which aids in thestacking of successive stretcher units. The weight of successivestretcher units pushing down centers the unit into the correct restingposition. The rounded lugs help to prevent successive stretcher unitsbecoming stuck or partially resting on the lug of lower stretcher units.The exemplary embodiments shown in FIG. 4B may also include a knock-outportion 410 for producing a bonding-beam portion in the constructedwall. The knock-out portion 410 may extend down three inches (+/−) fromthe top surface. The knock-out portion 410 may have a three quarter inchslot to allow for placing reinforcement members or removing theknock-out portion 410. Bonding-beams are horizontal reinforcements inthe wall that add strength between the vertical columns of theconstructed wall. A row of stretcher units in a wall of individual orsuccessive rows may be designated for a bonding-beam. Duringconstruction the knock-out portion 410 may be removed to allowreinforcement members and/or poured concrete to fill the cells of a rowof stretcher units. The knock-out portion 410 may be molded into thestretcher unit between the lugs 408 of the web 406.

The exemplary embodiments shown in FIGS. 4A and 4B may also includechamfered edges on the sides for the front section and the rear section.The chamfer allows the adjacent stretcher unit to fit snuggly againstthe neighboring stretcher unit. The chamfers of neighboring stretcherunits overlap providing additional strength and preventing leaking ofconcrete from the cell columns during pouring. The chamfers may have a⅜^(th) (+/−) inch inset. The exemplary embodiments shown in FIGS. 4A and4B may also include beveled edges on the outer surface of the frontsection and the rear section. The beveled edges of the stretcher unitgive the wall a more traditional block construction look. The bevelededge outlines the profile of the block without the need for groutedjoints. The edge is not limited to a bevel. The edge may have a chamferor other profile to outline the block face.

An exemplary embodiment of the invention with webs at right angles isshown in FIG. 5A and FIG. 5B. The stretcher unit 500 has a front section502 and a rear section 504. One or more webs 506 couple the frontsection 502 to the rear section 504. The webs 506, according to thisembodiment, run perpendicular between the front section 502 and the rearsection 504. The webs 506 may be spaced four inches (+/−) from the endof the stretcher unit 500. To provide cores that line up, each web 506has a pair of alternating, adjacent lugs 508. The lugs 508 extend abovethe surface of the stretcher unit 500 and allow the stretcher units tobe stacked in a staggered fashion without the lugs 508 interfering withthe web of a successive layer of stretcher units.

A first lug of the pair of lugs is coupled against a first surface of afirst web and an inner surface of the rear section. A second lug of thepair of lugs is coupled against a second surface of the first web andthe inner surface of the front section. A second pair of lugs for thestretcher unit has a first lug of the second pair coupled against afirst surface of a second web and an inner surface of the front section.A second lug of the second pair of lugs is coupled against a secondsurface of the second web and the inner surface of the rear section.Each of the lugs in the first pair of lugs is positioned on alternatingsides of the first web. Each lug of the second pair of lugs is alsopositioned on alternating sides of the second web; however, the lugs areon opposite sides from the first web. This allows the successive layerof stretcher units to rest on the stretcher unit and allows the lugs 508of the stretcher unit 500 to protrude into the cells of the successivelayer of stretcher units without interfering with the lugs of thesuccessive layer of stretcher units.

When the wall is constructed the stretcher units may be staged half wayoff-center for each successive row. This allows the alternating pairs oflugs to straddle the webs of successive rows of stretcher units. Thestretcher unit 500 is supported in the lateral direction by a lugpositioned between the inner surface of the front or rear section andthe web. The constructed wall locks together by the protruding lugsextending into the cells and straddling the webs of successive rows ofstretcher units above and below the stretcher unit.

The stretcher unit 500 may also have a beveled profile on the outersurface of the front section and rear section. The stretcher unit 500may also have a chamfered side edge for coupling to adjacent units. Inaddition, the stretcher unit may have a knock-out portion for producinga bonding-beam. These features are similar to those previously describedherein with respect to the exemplary embodiment disclosing the exemplarystretcher unit 400 with angled webs.

An exemplary embodiment of the invention with beveled lug profiles isshown in FIGS. 6A, 6B, 6C, and 6D. The exemplary embodiments 600 mayinclude a beveled lug profile 602. The lugs 604 have a beveled surfaceadjacent to the outer surface of the front section 606 and the rearsection 608. The beveled profile aids in the stacking of successivestretcher units. The weight of successive stretcher units pushing downcenters the unit into the correct resting position. The beveled lugprofiles 602 help to prevent successive stretcher units from becomingstuck or partially resting on the lug of lower stretcher units. Inaddition to a beveled profile on the surface of the lug facing the outersurface of the front section and the rear section, the lugs may alsohave a beveled surface adjacent to the web (not shown in Figures). Theadditional beveled profile aids in stacking and aligning the face shellsof the stretcher unit as previously discussed.

All or only a limited portion of top surface 610 of front section 606and the rear section 608 may be ground to provide a greater degree ofaccuracy in of the height for the stretcher unit. This greater degree ofaccuracy may be used to allow for dry stacking the units without theneed for shims or leveling supports. The units may be molded usingconvention block molding techniques. The grinding is preformed aftercuring. As will be discussed later herein, the lugs 604 may have arecess to provide better alignment. All or only a portion of the topsurfaces 610 of the front section 606 and rear section are ground to thedesired level. A tolerance of about less than +/−0.015 inches (0.4 mm)may be achieved to provide consistent flat and level surface for preciseheight for successive stacking of the units. Since the bottom of theunit is typically molded on a flat surface, a consistent and preciseblock height may be achieved by only grinding the top surface 610.

A corner unit 700 according to an exemplary embodiment of the inventionis shown in FIGS. 7A, 7B, and 7C. The corner unit 700 has a frontsection 702 and a rear section 704. The corner unit 700 also has a sidesection 706 coupling the front section 702 and the rear section 704. Oneor more webs 708 couple the front section 702 to the rear section 704.The corner unit 700 may be positioned at the corner of a constructedwall as shown in FIG. 2. The side section 706 provides a uniformappearance at the end of a row of units and provides support forsuccessive rows of units. The corner units may be stacked alternating by90 degrees for each row. This provides a lacing of rows between twolinear portions of the structure. The cell of the corner units 700 maybe filled with concrete to lock the corner units 700 together. Thecorner units 700 may also be ground during the manufacturing process toalso provide a consistent level surface for precision height control.

The web 708 is spaced to receive lugs from a previous row of stretcherunits off-set by half a unit length. The web is spaced within the cornerunit so as to align on top of the web of a previous row of stretcherunits allowing the lugs of the previous row of stretcher units tostraddle the web. The corner unit may also be used in the constructionof a linear position of a wall as shown in FIG. 3. The corner unit 700may also have a beveled or chamfered profile on the outer surface of thefront section 702 and rear section 704. The corner unit 700 may alsohave a chamfered side edge for coupling to adjacent units. In addition,the stretcher unit may have a knock-out portion for producing abonding-beam. These features are similar to those previously describedherein with respect to the exemplary embodiment disclosing the exemplarystretcher unit 400 with angled webs.

The stretcher units may assemble into a linear wall structure 800 asshown in FIGS. 8A and 8B. The linear cells 802 of the stretcher and/orcorner units produce a vertical post. The vertical posts typically maybe reinforced with a reinforcement member, for example, steel rebar. Thelinear cells 802 of the stacked stretcher units provide a moreconsistent size and are aligned linearly. When concrete is poured intothe cells the more consistent size of the linear cell makes it lessdifficult to install reinforcement members in the cores to form thevertical posts. In addition, the more uniform cell dimensions may makeit less difficult to fill the voids within the cell. Many conventionaldry stack block systems may provide little or no damming capacity whenfilling the cells of a dry stack block wall structure.

FIG. 9 is a perspective view of the stretcher unit stacked according toan exemplary stacking embodiment 900. The dimensions and structure ofthe stretcher unit provide the ability to stack a single column ofunits. By alternating each successive unit by 180 degrees the nextstretcher unit may be stacked on top of a successive unit. The lugs ofthe stretcher units align in the cells of each successive stretcherunit.

An exemplary embodiment of the invention includes a beveled or chamferededge profiles. The beveled edge may extend around the both sides and thetop edges of the stretcher unit as previously discussed in FIGS. 6Athrough 6D. The beveled edge of FIGS. 6A through 6D may about a 3/16 ofan inch step. The beveled edges of the stretcher unit give the wall amore traditional block construction look. The beveled edge outlines theprofile of the block without the need for grouted joints or may begrouted to provide a more detailed masonry profile look.

Referring to FIGS. 10A and 10B, the exemplary embodiments may include achamfered or beveled edge 1010 on one side and the top edges and a flatedge 1012 of the stretcher unit 1000. The chamfered edge 1010 of FIGS.10A and 10B may about a ⅜ of an inch step. This allows the chamferededge 1010 to butt directly against a flat edge of the next unit. Thechamfered edge 1010 mated against the flat edge of the next unit aids inconcealing the joint between the two units from the eye. The chamferededge 1010 outlines the profile of the block and draws the eye away fromthe joint between units without the need for grouted joints. Thechamfered edge 1010 may also be used to provide a tuck point/mechanicalgripping for veneer, stucco or grouted lines to provide a more detailedmasonry profile look. Positioning the joint to one side of the chamferededge 1010 may also conceal any future cracks or separation of the tuckpoint.

Referring to FIGS. 10B and 10C, a recess 1014 may be provided betweenthe top surface 1009 and lugs 1004. The recess may allow the grinding ofthe top surface 1009 without the lug 604 interfering with the grindingof the top surface 1009 during the manufacturing process. Interferenceof the lugs may prevent accurate grinding of the top surface 1004 and/orcause destruction or deformation of the lugs 1004 by the grinder. Inaddition, the recess 1014 may allow for removal of debris from thegrinding process or other manufacture process. Debris that remains onthe top surface 1009 may prevent successive units from sitting level oneach successive layer. The recess 1014 may be molded to extend about ⅛to ¼ of an inch below the top surface 1009 and provide a gap of about ⅛to ¼ of an inch. The recess 1014 may also be molded to open away fromthe center of the lug 1004 so that gravity aids in removal of the debrisout of the recess 1014.

Referring to FIGS. 11A, 11B and 11C, multiple levels may be provided onthe top surface 1109 of a stretcher unit 1102. Although this feature ofthe invention will be explained on and in connection with a dry-stackblock having a certain configuration and additional features thatfacilitate and enhance dry stacking, this is not a limitation of thisfeature of the invention as the stepped top surface profile and use ofgrout or adhesive describe herein can be performed with any type ofblock have essentially any configuration and additional features,including but not limited to, a wet-stack block.

According to an exemplary edge-grinding embodiment of the invention, thetop surface 1109 may be divided into regions of varying levels duringthe molding process. The stretcher unit 1102 may be molded with acentral region 1111 having a slightly higher surface than the adjacenttop surfaces 1113 which have a lower profile by approximately ⅛ inch.After the molding process, the top surface 1109 which may be in therange of 2″ to 7″ in length (and preferably only about 3″ in length) areground to provide a more accurate height of the stretcher unit 1102.

The lower surface areas 1113 are molded at a height slightly below theultimate desired height of the stretcher unit 1102, while the highersurface region 1111 in the central part of the block front and rearsections are molded slightly higher than the desired height of thestretcher unit 1102. Since masonry blocks are typically made from amixture of concrete, sand and small stones, the ultimate height and“levelness” of each block can and does vary, particularly because of theeffects of the small stones which may protrude upwards from the concreteclock. During the grinding process, these height irregularities will beeliminated. The grinder will either not or perhaps barely grind thelower surface 1113 due to the height being just shy of the set grindingheight. As the higher surface 1111 passes under the grinder, the grinderremoves a portion of the concrete block unit material that exceeds thedesired height providing a more accurate stretcher unit 1102 height inview of the molded height. By reducing the amount (length) of thestretcher unit 1102 to be ground down (i.e. a rather short 3″ or socentral region 1111), there is improved grinding performance resultingfrom an increase in the throughput speed as well as reduced wear on thegrinding heads.

For example, when manufacturing an eight-inch high unit, the block maybe molded with lower surface 1113 being a one-sixteenth ( 1/16) of aninch shy of eight inches and a higher surface 1111 being a one-sixteenth( 1/16) of an inch above eight inches. During the grinding process, thegrinder may remove portions of the higher surface 1111 providing aheight that is eight (8) inches to a greater degree of an one-eighth (⅛)or less of an inch accuracy. This accuracy allows for good overallheight control of the wall and levelness without block “rocking” whichis normally not a problem in a mortared wall since the mortar takes upany unevenness in the blocks.

The precision ground block units provide for precision height controleven when mortared together. The design provides for lower surfaces 1113and a higher surface 1111, which reduces the amount of influence themortar has on adding height to the courses of the wall. The highersurface 1111 may further have an appropriate number of indentations(grooves or channels) 1115 that serve to reduce the mortar influence inheight control to almost zero by providing channels or grooves intowhich any adhesive, grout or thin mortar may flow. Any grout, adhesiveor this mortar in the grooves or indentations 1115 will still serve toadhere the top surface of this block with the bottom region of a blockplaced on top of the block. This higher surface 1111 is then ground tothe desired height to provide units of precision height. The geometry ofthe higher and lower surfaces 1111, 1113 and the indents 1115 in the topsurface 1109 are designed in such a way as to provide a self-levelingaspect to the wall construction. The self-leveling feature allows forhigh stacking productivity even if the field conditions are not perfect.The self-leveling provides for a near fool-proof solution that allowsthe construction of the concrete block wall to be more forgiving. As anexample, if foreign materials are present in one level of the stacking,as subsequent courses are stacked, there is little or no potential for“rocking” of a block. The precision ground region of the higher surface1111 located in the top surface 1109 of the block's face will implementthe self-leveling feature and allow for an instant remedy to blocks thatwould otherwise by crooked or at an angle. The problem of angled orcrooked blocks can be remedied immediately without the need for shims orgrinding.

The edge-grinding embodiment is not limited to the lower surface 1113being lower than the desired height. The lower surface 1113 may bemolded to the exact height of the desired stretcher unit 1102. In thisexample additional grinding may be required with the bulk of thegrinding occurring on the higher surface 1111. Additionally, theedge-grinding embodiment may have different lengths of higher surfaces1111 and lower surfaces 1113. In the example shown in FIGS. 11A and 11B,each surface is roughly divided into thirds; however, the invention ifnot limited to this exemplary width and ratio. The higher surface 1111may be greater or less than a third of the overall length of the cementblock. In addition to grinding certain predetermined regions of thefront and rear top portion of the blocks, certain end portion, such asend portion 1315, FIG. 13B on corner block unit 1304, may also be groundto assist in providing a wall construction of uniform height.

In the previously discussed embodiment, a top web surface 1106 is moldedto a height of the lower surface 1113. This allows the grinding processto avoid the lugs and/or to facilitate multiple grinding processes.However, the embodiment is not limited to the top web surface 1106 beingmolded to a height of the lower surface 1113.

After manufacturing of the stretcher units 1102, the stretcher units1102 may be assembled as previously discussed herein. In the preferredembodiment of the method of the present invention, an adhesive (alsotermed grout or thin mortar) is applied between each course of thestretcher units 1102. The adhesive may be squeezed from the areasbetween the higher surface 1111 and the bottom of the next course ofunits. The adhesive may also remain in areas between the lower surface1113 and the bottom of the next course of units. Once the adhesivecures, the adhesive may provide additional load barring support thattypically meets or exceeds code specifications. The adhesive may be anexpandable adhesive to aid in the filling of voids between surfaces. Theadhesive in this case is selected to provide a desired expansion forcethat prevents movement of the stretcher unit 1102 after properpositioning while expanding to file any voids or spaces between surfacesof blocks stacked one on top of the other.

An exemplary code compliant mortar/grout/adhesive according to onefeature of the present invention was designed and developed to beapplied without a trowel but rather, using a high-speed applicator.Examples of such a high-speed applicator include a grout bag or a groutpump well known in the industry for applying grout to tiles or to theexterior face of previously erected block walls. The stackable blockdesign of the present invention allows for the new mortar to be easilysqueezed between the subsequent blocks to a thickness of less than ⅛ ofan inch so that the mortar is not dictating the height of the wall.Rather, the height of the wall is dictated by the high-speed grindingheight gauging process that each block passes through to make it aprecision height unit with tolerances that are an order of magnitudebetter than in the ASTM C-90 block standard. Fine grained thin setmortar readily available in general home building supply stores likethat used for laying tile on floors or walls will work well with thepresent invention.

The mortar may also be provided that has properties that conform to theMasonry Standard for Unit Mortared Masonry but is also designed so thatit can be applied at high speeds without a trowel or experiencedapplicator and applied so that it does not interfere with the heightcontrol aspects of the precision block of the invention. Such a codeapproved mortar can be applied at a thickness as thin as 1/64 of aninch. The mortar is ultra fine grained and made with cements, aggregatesand chemical modifiers as in thin set motors that give it its uniqueproperties. The particles in the mortar are less than 5/1000 of an inch.The mortar should have good water retention and does not dry out throughevaporation or through suction from the dry block to which it isapplied. The water retention of the mortar allows the mortar to remainflowable after application to the block allowing all unnecessary motorto flow or squeeze out from between two blocks. If the mortar where tolose its ability to flow, the mortar would add too much thicknessbetween the blocks and would affect the ability of the wall to be builtto meet specified elevations.

Referring to FIGS. 12A and 12B, multiple levels may be provided on thetop surface 1209 of a stretcher unit 1202. According to a secondexemplary edge-grinding embodiment, the top surface 1209 may be dividedinto regions of undulating levels during the molding process. Thestretcher unit 1202 may be molded with a curved top surface 1209 thathas a higher surface 1211 sloping down to the adjacent top lowersurfaces 1213. After the molding process the top surface 1202 may beground to provide a more accurate height of the stretcher unit 1202 aspreviously described with regard to the embodiments in FIGS. 11A and11B. Other embodiments of previously described in FIGS. 11A and 11B mayalso be incorporated in the embodiments of FIGS. 12A and 12B.

Referring to FIGS. 13A and 13B, multiple levels may be provided on thetop surface 1309 of a corner unit 1304. According to an exemplaryedge-grinding embodiment, the top surface 1309 may be divided intoregions of varying levels during the molding process. The corner unit1304 may be molded with a top surface 1309 that has a higher surface1311 slightly higher than adjacent top lower surfaces 1213. After themolding process, the top surface 1311 may be ground to provide a moreaccurate height of the corner unit 1304 as previously described withregard to embodiments in FIGS. 11A and 11B. Other embodiments ofpreviously described in FIGS. 11A and 11B may also be incorporated inthe embodiments of FIGS. 13A and 13B.

Modifications may be made to fit particular operating requirements andenvironments as will be apparent to those skilled in the art, theinvention is not considered limited to the examples chosen for purposesof disclosure, and covers all changes and modifications which do notconstitute departures from the true spirit and scope of this invention.Modifications and substitutions by one of ordinary skill in the art areconsidered to be within the scope of the present invention.

1. A method of producing a stackable building block for constructing amasonry wall, the method comprising the acts of: molding a concreteblock having a front section coupled to and substantially parallel witha rear section, each of the front and rear sections having a bottomsurface and a top surface, wherein the top surface on both the front andrear sections includes a central region having a height which is greaterthan first and second end regions located on either side of the centralregion; and grinding the central region of the top surface of the frontand rear block sections to a predetermined height.
 2. The method ofproducing a stackable building block for constructing a masonry wall ofclaim 1, wherein the building block is a dry stackable concrete block.3. The method of producing a stackable building block for constructing amasonry wall of claim 1, wherein the building block is a wet stackableconcrete block.
 4. The method of producing a stackable building blockfor constructing a masonry wall of claim 1, wherein the central regionhas an undulating surface.
 5. The method of producing a stacked buildingblock wall utilizing the stackable building block of claim 1, andfurther comprising the acts of: applying a flowable, thin set mortaronto the top surface of the stackable building block using a high speedapplicator.
 6. The method of producing a stacked building block wallutilizing the stackable building block of claim 5, wherein the highspeed applicator is a grout bag.
 7. The method of producing a stackedbuilding block for constructing a masonry wall of claim 5 wherein themortar is applied to a thickness of ⅛ of an inch or less.
 8. The methodof producing a stackable building block for constructing a masonry wallof claim 1 wherein the grinding of the higher surface of the top surfaceis precision ground to provide a stack building block of a specificprecision height.
 9. The method of producing a stackable building blockfor constructing a masonry wall of claim 1 wherein the central region ofthe top surface further includes a plurality of indents or serrations orchannels.
 10. The method of producing a stacked building block wallutilizing the stackable building block of claim 9, and furthercomprising the acts of: applying a flowable, thin set mortar onto thetop surface of the stackable building block using a high speedapplicator; and allowing the mortar to enter the plurality of indents orserrations or channels on the central region of the top surface, whereinthe addition of the mortar does not significantly increase the specificprecision height of the stackable building block.
 11. The method ofproducing a stacked building block wall utilizing the stackable buildingblock of claim 1, and further comprising the acts of: stacking a secondduplicate stack block staged halfway off-center; and stacking a thirdduplicate stack block staged halfway off-center in a direction oppositeand adjacent to the second stack block.
 12. The method of producing astack building block for constructing a masonry wall of claim 1 whereinthe stack building block has a chamfered or beveled edge on one moreexterior edges of the building block.